Gasoline fuel dispensing nozzles are used to control the flow of fuel, such as gasoline or gasoline blended with ethanol, from a storage tank through a fill pipe into a gasoline tank in a vehicle. In order to facilitate the rapid and efficient dispensing of the fuel from a storage tank to a user tank, fuel dispensing systems are designed to operate at a very high fluid flow rate. The fuel is pumped from the storage tank and through a dispensing metering system that tracks and records the amount of fuel dispensed by each user. The fuel then flows through a fuel line from the metering system to a dispensing nozzle that is placed in a fuel inlet or fuel filler neck attached to the user tank to enable the dispensing of fuel from the storage tank into the user tank.
The dispensing nozzle that is used to dispense fuel may have a safety interlock mechanism incorporated therein. The safety interlock mechanism will immediately stop the flow of gasoline if the fuel dispensing nozzle is accidentally removed from the fill neck prior to the tank being full. The nozzle may contain a bellows device that is placed over a spout that is inserted into the fill neck. By placing the spout into the fill neck a force is exerted on the bellows device that moves the bellows device to initiate operation of the interlock mechanism. Removal of the spout prior to the tank being full releases the force on the bellows device and operates the interlock mechanism to shutoff fuel flow. The bellows device is constructed of a hard material that requires a large force to move the bellows device to operate the interlock mechanism. The force that is required is so large that elderly individuals find it difficult to use the nozzle to refuel a vehicle. To complicate matters, the force required to engage the interlock mechanism increases at lower temperatures. Thus, bellows type devices are perceived as being difficult to operate, large, heavy, and bulky. As known, the bellows style of balanced pressure fuel dispensing is used to provide a return of vapors back to the underground storage tank, primarily through the pressure that builds up within the fuel tank as gasoline is being dispensed therein. That pressure returns the vapors back through the bellows, its nozzle, and the dispenser to the underground storage tank.
Further, some governmental regulatory agencies require that a nozzle have a vapor recovery system integrated with the nozzle so that any vapors inside the fuel tank of the vehicle are allowed to flow back through the nozzle and into an underground storage tank. Such nozzles, in order to comply with various regulations, must function to shutoff both fuel delivery and provide vapor recovery during refueling and in the event that the nozzle is inadvertently removed from a fill pipe of a vehicle. However, due to recent regulations, nozzles having vapor recovery systems are being phased out. Also, due to a large number of new vehicles being equipped with on-board refueling vapor recovery systems (ORVR), the extra level of safety gained from vapor recovery interlock nozzles will be reduced. Therefore, there is the potential for nozzle manufacturers to produce nozzles which do not have expensive vapor recovery interlock systems incorporated therein.
The present disclosure is designed to obviate and overcome many of the disadvantages and shortcomings experienced with prior nozzles having a safety interlock mechanism for dispensing fuel. Moreover, the present disclosure is related to a safety interlock nozzle that is designed and constructed to be easier to operate, from a force standpoint, than prior nozzles having a safety interlock mechanism. The present disclosure utilizes different structure, to assure that the nozzle always remains off, until such time as the spout is properly and conveniently located within the fill pipe of the vehicle, before the fuel can be dispensed. The present disclosure further provides different structure to immediately shutoff fuel flow if the nozzle is inadvertently, accidentally, untimely, or even negligently removed from the fill pipe of the vehicle before the tank is full.